A. Field of the Invention
The present invention relates to a flour-starch mixture and to an improved microwaveable flour-starch based food product that is prepared therefrom. The flour-starch based food product of the present invention is capable of heating evenly, even from a frozen state, when exposed to microwave energy and resists the deterioration in palatability that accompanies microwave exposure. The present invention further relates to a flour-starch based food I0 product in combination with a microwave susceptor. The present invention is useful because it provides a palatable flour-starch based food product that is capable of heating and crisping evenly when exposed to microwave energy. The resultant flour-starch based food product also exhibits resistance to mold formation.
B. Prior Art
It has become commonplace for consumers to have microwave ovens at their disposal for home cooking. Microwave cooking is remarkably quick and convenient. Accordingly, both consumers and industry seek to use microwave ovens for everything from cooking vegetables and meats to reheating pizza, sandwiches, rolls, and other food products containing flour as an ingredient.
As noted in U.S. Pat. Nos. 4,463,020 and 4,560,559, the industry has long recognized and sought to solve problems that arise from microwaving flour-based products, especially those that are yeast-raised like bread rolls. Many flour-based products, such as pizza, breads, and pasta, become impalatable after short exposure to microwave energy. Bread, for example, develops a rubbery or gummy crust that is difficult to tear and chew after microwaving. In addition, the inside of the bread frequently becomes soggy or develops hard lumps. Cf. U.S. Pat. No. 4,463,020 at col. 1, ln. 32-42.
Sandwiches and other foods having flour-based components also tend to heat unevenly. As the above-referenced patents explain, the rate at which food products absorb microwave energy is dependent upon their moisture content. Sandwich rolls frequently have a high moisture content relative to the sandwich filling. When microwaved, the sandwich rolls tend to overheat before the filling reaches serving temperature. The result is a sandwich roll of reduced palatability.
The industry has tried a variety of ways to reduce these problems. They have met with limited success. One attempt involves use of "rich" formulations. These formulations are "rich" in expensive non-flour components (such as syrup, shortening, or egg) but are low in water content. Because of their low water content they tend to absorb microwave energy more slowly. The use of "rich" formulations adds cost to production. Finally, "rich" formulations have not eliminated the problem of a hardened crust and a soggy center that develops during microwaving. CF. Id. at col. 1, ln. 61 to col. 2, ln. 2.
Pre-toasting of the flour-based product has also been used to reduce water content. The use of day-old bread has similarly been tried. Although these methods provide for some improvement in palatability, neither of these methods has proven very satisfactory. Both methods still result in a flour-based food product having reduced palatability upon microwaving. Both methods also require the additional step of bread preparation which increases both cost and handling time.
U.S. Pat. No. 4,463,020 (Ottenberg I) discloses the use in combination of wheat flour, yeast and rice flour to produce a flour-based food product having a reduced deterioration in palatability when that food product is exposed to microwave energy. U.S. Pat. No. 4,560,559 (Ottenberg II) discloses that "the key to the effectiveness of the rice flour [in the '020 patent] is the rice starch of which it is composed and that certain other starches can be added. . ." ['559 at col. 2, ln. 36-40]. The Ottenberg II patent more specifically discloses the use in combination of "wheat flour, yeast and at least one starch having a sufficiently small crystal size . . .[i.e.,] an average crystal size of less than about 20 microns [to] improve the resistance of a yeast raised wheat-based food product to deterioration from microwave energy." ['559 at col. 2, ln. 53-60]. The Ottenberg formulations are alleged to improve the microwavability of wheat based food products "from either a refrigerated or room temperature state." ['559 at col. 8 ln. 62-63]. However, Ottenberg II teaches that "Frozen food products are generally not advantageously prepared by microwave cooking because the ice in the product resists microwave energy." ['559 at col. 8, ln. 67 to col. 9, ln. 1]. Regarding food products prepared according to his invention, Ottenberg specifically teaches that "Food products according to the invention that are frozen, should therefore be defrosted or thawed before being heated in a microwave oven." ['559 at col. 9, ln. 1-4]. Hence, the wheat flour yeast and starch compositions of Ottenberg are not satisfactory for providing a flour-based food product that is microwaveable directly from its frozen state.
An object of the present invention is to provide a food product that is microwaveable from its frozen state without a loss in palatability.